Tesoro blast called fireball

The Tesoro refinery workers who were killed and injured in Friday's fire were engulfed in a fireball that likely measured half the length of a football field as it blossomed into the night sky, according to a federal investigator at the scene on Monday.

Robert Hall, the supervising investigator from the U.S. Chemical Safety and Hazardous Investigations Board (CSB) told reporters Monday that all of the seven workers were within 50 feet of the point of ignition. Hall stressed that none of them had a chance to escape before a large, "unscheduled" release of hydrocarbons ignited while they were working on a naphtha hydrotreater in the refinery complex.

Five workers were killed and two badly burned in what Hall said was "more of a fireball than an explosion," even though residents in Anacortes reported that it shook their windows.

One of the two survivors of the fire was showing improvement Monday at Harborview Medical Center in Seattle. Spokeswoman Susan Gregg-Hanson said Matt Gumbel, 34, of Oak Harbor, had been upgraded from critical to serious condition.

Another survivor at the hospital, Lew Janz, 41, of Anacortes, remained in critical condition, she said. Both men are in the intensive-care unit with burns. Tesoro spokesman Lynn Westfall said Monday that both men are scheduled for skin-replacement surgery.

Of the five employees killed by the fire, three died at the scene and two later at Harborview.

Bob Clark, the Skagit County deputy coroner, said Monday that Matthew C. Bowen, 31, of Arlington; Darrin J. Hoines, 43, of Ferndale; and Daniel J. Aldridge, 50, of Anacortes, all died at the scene from inhalation of toxic products of combustion and from thermal injuries to their entire bodies. Their deaths were ruled accidental.

Hall said the CSB's investigation into the blast could take 18 months because of the time and expense needed to deconstruct the area where the fire occurred, conduct metallurgical and other tests, and compile statements and refinery operational data for review. He said the CSB also will review the plant's management practices to determine whether they played a role in the incident.

The CSB will also ask for the results of a third-party safety audit conducted at the Tesoro plant a month before the fire, as well as the details of a 2008 state safety investigation in which Tesoro was cited for 17 serious violations with fines totaling $85,700, according to the U.S. Occupational Safety and Health Administration. Fourteen of the violations were deleted and the fines reduced to $12,250 after Tesoro agreed to fix the problems instead of contesting them.

Investigators arrived on the scene Saturday and have had a chance to visit the area where the fire occurred, Hall said. He said investigating is dangerous work, in that there are still puddles of unburned fuel, charred asbestos and other hazards. Otherwise, he said, there was no significant blast damage, which is what led investigators to conclude no explosion occurred.

So far, he said, the investigators can say only that there was a release of a large cloud of hydrocarbons — fuel that ignited almost immediately. Investigators do not yet know how, he said.

The investigation also will involve interviews, including discussions with survivors if possible, and a review of control-room data from the time of the fire.

Mike Carter: 206-464-3706 or mcarter@seattletimes.com.